1. Field of the Invention
This invention relates to an image forming apparatus such as a copying machine or a printer that can provide improved maintenance efficiency for the apparatus main body.
2. Description of the Related Art
A conventional image forming apparatus such as copying machines and printers include those equipped with an automatic duplex unit (to be referred to as ADU hereinafter). An ADU operates to feed a sheet bearing a fixed toner image at least on one of the opposite sides thereof feed to the image transfer position of the image forming apparatus once again.
In some image forming apparatus of the type under consideration, the ADU is arranged at a lateral side of the apparatus main body at a position adjacent to the sheet conveyance route in the apparatus main body. With this arrangement, the apparatus main body can be downsized and an ADU can be commonly used in a plurality of image forming apparatus manufactured with different sets of specifications.
With conventionally techniques, when an ADU is arranged at a lateral side of the apparatus main body and a jam accident arises, the ADU is turned around the lower end thereof that operates as fulcrum and then the lateral side of the apparatus main body is opened to dissolve the jam. For example Jpn. Pat. Publication (Kokai) No. 2005-115218, Jpn. Pat. Publication (Kokai) No. 2005-31353 and Jpn. Pat. Publication (Kokai) No. 2001-2330 discloses such techniques.
In some image forming apparatus technology in recent years, the lateral side of the apparatus main body where an ADU is arranged provides an access point for not only dissolve the jam but also maintenance the units in the apparatus main body.
However, in such conventional apparatus, the angle by which the ADU can be turned relative to the apparatus main body is limited to such an extent that the inside of the apparatus main body can be accessed only for dissolving the jam. In this reason, the ADU has to be removed from the apparatus main body when the lateral side of the apparatus main body needs to be opened wide for the purpose of maintenance the units in the inside of the apparatus main body, thus the workability of maintenance could have been went down. In this reason, the ADU and the apparatus main body are linked to each other by wires for driving the sheet feeding rollers and other components. Then, it is a cumbersome operation to find an appropriate location for temporarily put the ADU. Additionally, the wires connecting the apparatus main body and the ADU may be subjected to an undesired load.
Therefore, it is desired for image forming apparatus equipped with an ADU that is arranged at a lateral side of the apparatus main body that the ADU can be turned at a large angle relative to the lateral side of the apparatus main body to improve the maintenance efficiency.